Swing-knife mounting



Dec. 14, 1965 J. w. BARTH 3,222,854

SWING-KNIFE MOUNTING Filed March 2, 1964 INVENTORJ JOHN W. IARTH BVWJJQ United States Patent M 3,222,854 SWING-KNIFE MOUNTING John W. Barth, Cudahy, Wis, assignor to Jacobsen Manufacturing Cm, Racine, Wis., a corporation of Wisconsin Filed Mar. 2, 1964, Ser. No. 348,516 3 Claims. (Cl. 56-294) This invention relates to a swing-knife, and more particularly it relates to a swing-knife for use in cutting grass, weeds, crops, and the like.

Swing-knives which operate under the influence of centrifugal force to be radially extended from a rotating shaft on which they are mounted are of course generally known. These knives are arranged to be extended and thus they cut weeds and crops or the like, and of course the mounting of the knife is such that when it strikes an immovable object, the knife will pivot with respect to its mounting so that the knife and remaining assembly are not damaged unduly. Of course these knives do become worn and damaged and it is therefore important that they be arranged for being removed and replaced by another knife. Therefore the knife mounting, and the entire assembly, should be provided in a manner that the knife can be readily and easily rernpved and replaced by another knife, but of course the mounting should also be arranged so that it is suifioiently sturdy to adequately support the knife and yet permit it to pivot away from the stone or like object which may be struck by the knife.

Accordingly, it is an object of this invention to provide a swing-knife which is pivotally mounted with respect to its supporting shaft and which is then also sturdily supported in its mounting and readily and easily replaced by another knife when it is so desired.

Another object of this invention is to provide a releasable mounting for a swing-knife of the type heretofore mentioned, and with the mounting being generally an improvement over the mountings heretofore known, and with the mounting being relatively simple in its arrangement and number of parts and inexpensive to manufacture and maintain.

Still another object of this invention is to provide a swing-knife which is fully and readily removable from its supporting shaft and which has no welding or even bolting for attaching the knife to the shaft and which does not require any highly elaborate or specially arranged shaft and other parts in order to accomplish the aforementioned features in the swing-knife art.

A more specific object of this invention is to provide a swing-knife which can be removed and replaced with respect to its mounting shaft without any special tools being required but which nevertheless securely holds the knife in the operating position when the shaft is rotating.

Other objects and advantages become apparent upon reading the following description in light of the accompanying drawing wherein:

FIG. 1 is an end elevational view of a preferred embodiment of swing-knife of this invention.

FIG. 2 is a side view of that shown in FIG. 1.

FIG. 3 is a top plan view of the spring clip shown in FIG. 1.

FIG. 4 is a bottom plan view of one plate shown in FIG. 1.

FIG. 5 is a side elevational view of the fragment of the 3,222,854 Patented Dec. 14, 1965 The knife or cutter itself is indicated at 12 and includes the shank portion 13 and the toe portion 14 which has the cutting edge 16 thereon.

With particular reference to FIG. 2 it will therefore be understood that upon rotation of the shaft 10 the cutting edge 16 is presented to material such as grass or crops which are to be cut, and the edge 16 therefore severs the material as desired. Of course it will also be understood that the knife 12 is supported on the shaft 10 by means of a pair of plates 17 and a pin 18 so that of course the entire assembly rotates along with its shaft 111, and the knife 12 is disposed in the radially extended position shown under centrifugal force created by rotation. Of course if the toe 14 strikes a stone or the like, then the knife can pivot with respect to the remainder of the assembly about the pin 18.

Thus plates 17 are also provided with hexagonal openings indicated 19, so the plates positively rotate with the shaft 10. The plates extend radially from the shaft 10 and have aligned openings 21 which receive the pin 18. Of course it will now be understood that in turn the pin 18 is received within opening designated 22 in the knife 12 so that the latter is pivotal on the pin 18 as mentioned.

Thus the knife shank 13 occupies the space between the plates 17 in the extending protions of the latter, and the plates 17 also have projections 23 which are disposed toward each other to retain the remainder of the plates 17 in spaced-apart relation for the accommodation and reception of the knife 12 as shown in FIG. 2.

In order to retain the plates 17 toward each other, that is of course axially on the shaft 10, a spring clip 24 is disposed to extend between the pin 18 and the shaft 10 as shown. The clip 24 extends around one side of the shaft 10 as shown in FIG. 1 by nesting in the shaft grooves 11 immediately axially beyond the plates 17, and the spring then extends to the pin 18 but to the other side thereof with respect to its extent around the shaft 10. FIG. 7 shows pin 18 has two grooves 26 extending therearound in the end portions of the pin 18, and thus it will be understood that the spring clip free end portions 27 are nested in the groove 26. Therefore the intermediate portions 28 of the spring clip 24 are in the shaft grooves 11, and the connecting length or portion 29 of the spring clip 24 extends between the opposite sides of the plates 17 as shown in FIGS. 2 and 3.

Still further it will be noted that the plates 17 have notches 31 therein for receiving the spring clip portion 29 to anchor the latter with respect to the plates 17.

Accordingly it will be understood that the plates 17 are mounted on the shaft 10 to rotate therewith and extend radially therefrom to present the aligned holes 21 for reception of the pin 18. Of course the pin 18 pivotally supports the knife 12. The spring clip 24 then extends on opposite sides of the shaft 10 and the pin 18 and is anchored with respect to the plates 17, and of course the clip is also disposed in the grooves 11 and 26 in the shaft and pin respectively. With the arrangement of the spring clip described, the clip is therefore utilized to axially retain the plates 17 on the shaft 10 in that the clip portions 23 are in interference fit with the axial movement of the plates 17, and the clip 24 also retains the pin 18 with respect to the plates 17 since the clip extends in the pin grooves 26. Of courses it will be appreciated that simply unclamping the clip portion 29 from the plates 17 will permit the entire clip 24 to be rotated about the axis of the shaft 111 and therefore relieved from the pin 18 since the spring end 32 extends only half way around the circumference of the pin 18 and therefore the entire spring portion 27 can be removed from the pin 18. It will also be understood that the clip portion 29 is anchored in the notch 31 by means of a camming action which is presented by the curved surface 33 of the plates 17 as the clip portion 29 slides along the surface 33 until it reaches the seated position in the notch 31 to be secured therein until forcibly removed in the opposite direction. Also, the clip extended side portions 34 are available for control of the clip in sliding it both on and off with respect to the notch 31 and simple finger pressure, rather than any tool, is adequate for movement of the clip. In this regard with respect to the camrning action it will also be noted that the surface 33 is arcuate and has its center approximately at the center point indicated 36 in FIG. 1.

It will of course be understood that a series of assemblies including the plates 17 and clips 24 and blades 12 and pins 18 are disposed on the shaft in a radially staggered relation such that the plates 17 extend at different angles with respect to the axis of the shaft 10 and thus of course the blades 12 extend outwardly in different directions in the usual and well known manner of mounting swing-knives or the like on a single shaft.

With respect to the spring clip 24, it will therefore be understood that the clip is S-shaped in for instance the right hand view from that shown in FIG. 2, and it is of course also U-shaped in the top view shown in FIG. 3. Therefore the spring extends to the opposite sides of the pin 18 and the shaft 10 as mentioned to have the tension of the spring arranged so that it is of course in the tensioned position as shown in FIG. 1. It will therefore remain as shown until the portion 34 is depressed or removed from the notch 31 and the entire spring is rotated about the axis of the shaft 10 until the end 32 is relieved from the pin 18. It will of course also be noted that the clip 24 can be placed on the plates and the pin in the opposite way with respect to the view shown in FIG. 1, namely the spring portion 29 could be disposed in the notch 31 on the left in FIG. 1 and the spring would then extend in the true S configuration when viewed from the side shown in FIG. 1.

While a specific embodiment of this invention has been shown and described, it should be obvious that certain changes could be made in the embodiment and the invention should therefore be determined only by the scope of the appended claims.

What is claimed is:

1. A swing-knife assembly comprising in combination a rotatable and polygonally-shaped shaft, a pair of plates having polygonally-shaped openings receiving said shaft for rotation therewith and extending from said shaft and having axially aligned openings in the extending portions, a pin removably disposed in said aligned openings and extending beyond both said plates, a knife removably mounted on said pin intermediate said plates and being radially extendable under centrifugal force of rotation of said shaft and being radially retractable, said shaft and said pin having grooves therein axially beyond said plates and adjacent thereto, and a spring clip disposed in said grooves and extending between said shaft and said pin and partly around both on opposite sides thereof and adapted to be releasably spring-loaded on both and being in axial interference fit with said plates for retaining and spacing the lat ter on said shaft and said pin.

2. A swing-knife assembly comprising in combination a rotatable and polygonally-shaped shaft, a pair of plates having polygonally-shaped openings receiving said shaft for rotation therewith and extending from said shaft and having axially aligned openings in the extending portions and having notches spaced from said extending portions, a pin removably disposed in said aligned openings and extending beyond both said plates, a knife removably mounted on said pin intermediate said plates and being radially extendable under centrifugal force of rotation of said shaft and being radially retractable, said shaft and said pin having grooves therein axially beyond said plates and adjacent thereto, and an S-shaped spring clip removably disposed in said grooves and being disposed in said notches and extending to said pin and partly around said plates and said pin on opposite sides thereof and adapted to be releasably spring-loaded on both and said spring clip extending radially beyond said grooves to be in axial interference fit with said plates for retaining and spacing the latter on said shaft and said pin.

3. A swing-knife assembly comprising in combination a rotatable and polygonally-shaped shaft, a pair of plates having polygonally-shaped openings receiving said shaft for rotation therewith and extending from said shaft and having axially aligned openings in the extending portions, 2. pin removably disposed in said aligned openings and extending beyond both said plates in opposite directions, a knife removably mounted on said pin between said plates and being radially extendable under centrifugal force of rotation of said shaft and being radially retractable, said shaft and said pin having grooves therein axially beyond said plates and adjacent thereto, said plates having an arcuate surface on the edge diametrically opposite said aligned openings and having a notch adjacent said arcuate surface, and a spring clip disposed with portions in said grooves on opposite sides of said pair of plates and extending between said shaft and said pin and partly around both on opposite sides thereof and adapted to be releasably spring-loaded on both and extending radially out of said grooves to be in axial interference fit with said plates for retaining and spacing the latter on said shaft and said pin, said spring clip including an intermediate portion connecting between said portions in said grooves and disposed in said notch and being slidable on said arcuate surface for attachment and release with respect to said plates and the tension of said spring.

References Cited by the Examiner UNITED STATES PATENTS 2,859,582 11/1958 Babcock 56295 2,871,644 2/1959 Matt 56249 X 2,926,033 2/1960 Zarillo 8.8 X 2,990,667 7/1961 Schwalm 56294 ABRAHAM G. STONE, Primary Examiner.

ANTONIO F. GUIDA, Examiner. 

1. A SWING-KNIFE ASSEMBLY COMPRISING IN COMBINATION A ROTATABLE AND POLYGONALLY-SHAPED SHAFT, A PAIR OF PLATES HAVING POLYGONALLY-SHAPED OPENINGS RECEIVING SAID SHAFT FOR ROTATION THEREWITH AND EXTENDING FROM SAID SHAFT AND HAVING AXIALLY ALIGNED OPENINGS IN THE EXTENDING PORTIONS, A PIN REMOVABLY DISPOSED IN SAID ALIGNED OPENINGS AND EXTENDING BEYOND BOTH SAID PLEATES, A KNIFE REMOVABLY MOUNTED ON SAID PIN INTERMEDIATE SAID PLATES AND BEING RADIALLY EXTENDABLE UNDER CENTRIFUGAL FORCE OF ROTATION OF SAID SHAFT AND BEING RADIALLY RECTRACTABLE, SAID SHAFT SAND SAID PIN HAVING GROOVES THEREIN AXIALLY BEYOND SAID PLATE AND ADJACENT THERETO, AND A SPRING CLIP DISPOSED IN SAID GROOVES AND EXTENDING BETWEEN SAID SHAFT AND SAID PIN AND PARTLY AROUND BOTH ON OPPOSITE SIDES THEREOF AND ADAPTED TO BE RELEASABLY SPRING-LOADED ON BOTH AND BEING IN AXIAL INTERFERENCE FIT WITH SAID PLATES FOR RETAINING AND SPACING THE LATTER ON SAID SHAFT AND SAID PIN. 